A currency change machine typically comprises an acceptor device, a central processing unit (CPU) and one or more payout hoppers. The accepting device is generally a coin, note or card acceptor, which validates a coin, note or card being inserted into the machine and issues a signal to the CPU which in turn signals the payout hopper to pay out coins or tokens.
Typically payout hoppers are slow in counting out and dispensing the required payout. In existing machines attempts have been made to increase the speed of payouts by increasing the number of payout hoppers within the machines. Besides being costly this also leads to the physical size of the machine being drastically increased. For many applications the size, in particular the horizontal size of a change machine is critical. Generally large change machines are undesirable in their places of intended use.
Additional problems arise as increasing the number of payout hoppers naturally leads to increasing the quantity of coins the accumulated number of hoppers are able to hold in reserve for future payouts. To further increase the hopper capacity vertical extensions of the hopper container have been provided.
The coins are paid out from the bottom of the hopper and the hoppers are filled from the top. Due to this fact, the practically managable distance from the bottom of the hopper to the top of the hopper or extension is limited, as the height at which the coins are paid out to the user must not be too low, and the height at which the hopper is filled must not be too high as service personnel must be able to easily fill the hopper with coins. Whilst for these reasons horizontal as well as vertical extension of the hopper container capacity is preferable, this has not been done as coinage does not transport as would liquid, and if the hopper container is extended horizontally as well as vertically, this may cause "bridging" where coins force themselves into a high compression area, and thus block in that position, due to the weight of the coinage above.
Furthermore, due to the weight of coins, a hopper with a large extension is very difficult to handle if full of coins, should there be a need to remove the hopper for reasons such as emptying the hopper or removing a faulty hopper.